Some mobile phone calling plans include reduced charges (i.e., free or minimal charge of monthly account time or allocated “minutes”) when an incoming call comes from a caller that belongs to the same mobile network as the call recipient. Such promotional features make calls between subscriber mobile phones free of charge, for registered mobile handsets. Other plans permit subscribers to share minutes with other subscribers, when the mobile subscriber plans are obtained or linked together for billing purposes. The importance of identifying in-network calls is thus highlighted, as subscribers may avoid charges altogether if they can distinguish in-network calls from out-of-network calls, and the carrier can inform non-network callers of its free in-network calling feature, if such a feature were available.
Another approach to mobile telephony price promotion is the in-circle plan, such as a calling circle plan. Such plans allow subscribers to specify certain numbers that are called frequently from the subscriber's handset (the numbers comprise the subscriber's “circle”), and provides a discount on calls made “in-circle.” Identifying the appropriate billing rate involves the carrier storing those numbers for each subscriber and checking a database at the time of call to apply promotional rates. An “in-circle” calling plan is not a general check of in-network calls, however, it is just a preferential billing promotion applied to a handful of frequently called numbers.
Other plans also allow subscribers to identify and preset caller “favorites,” such as a set of frequently called numbers, which can include both in- and out- of network numbers, on a carrier's promotional billing plans. This type of reduced-cost calling is not an in-network notification, as it may include numbers outside of the carrier's network. Other proposals for discounted billing to frequently called numbers might.
Other proposals for discounted billing to frequently called numbers might apply lower billing rates for the most frequently called numbers each billing cycle, for all numbers called over a certain pre-set number of minutes each billing cycle, and so forth.
A few methods have previously been proposed for alerting the call recipient if the call source shares the same network. For example, a network-based Global Title Translation (GTT) query will identify the carrier associated with the Caller Identification (CDN) or Mobile Directory Number (MDN) to the Network Control Point (NCP) of the caller's mobile carrier. A GTT search is typically requested at a Signaling Transfer Point (STP) associated with the NCP, while the incoming call page is held pending the result of the query. Once the result is given, the call page with the information is released to the sender. While this permits the connection of the call and appropriate billing for an in-network call by the carrier, there is a cost associated with the GTT search by the carrier, and there is no display indicator of the in-network call to the call recipient indicating whether or not the call is in-network.
Another approach is set forth in US Patent Application Publication No. 2008/0059642 (IBM). This approach also requires a network-based determination of the carrier of the calling and the called party by the network carrier, and provision of the in-network notification to both the calling and the called parties. Three methods are recited, one, similar to GTT, requires a network database query by the caller's carrier, prior to call termination. This has the accuracy limitation, since mobile numbers are portable, and when callers switch networks this method introduces errors. The second method, performed after call termination, looks at the switching information for the caller and the called number, which is highly accurate. With this method, however, the data that the call is in-network is only determined after the call has been established and further requires that the in-network determination be incorporated into the established call via either a side channel or mixed into the digital signal itself. The third method, performed while the called party's phone is on, but not on a call, requires the phone to have a side data channel. This requires the phone, at startup, to contact the network to do a database lookup to see if the phone numbers in the address book are in-network. This method is limited to updating the ‘in-network’ status only of the phone numbers stored in the caller directory on the called party's handset, however. As a result, this method does not ensure that new callers and their numbers are identified as “in-network,” which is the situation in which caller identification is the most helpful to the called party.
Considering the shortcomings of the aforementioned methods, it is clear that there is a need for a method for allowing mobile device users to determine whether their calls are “in-network” and thus potentially subject to certain cost-saving promotions or rate reductions offered by service providers, or to the display of enhanced information regarding the calling party. Therefore, an improved system and method for automatically notifying subscribers of the “in-network” status of calls is highly desirable.